The present invention relates to endoscopic surgical instruments.
Several different kinds of surgical instruments have been developed for performing arthroscopic and other endoscopic surgical procedures. Some of these surgical instruments are powered, that is, operated by a motor; others are manual. Motor-driven instruments typically are received by a handpiece which houses the motor. Manual instruments are operated with a trigger-like handle. Examples of powered endoscopic surgical instruments are described in U.S. Pat. Nos. 4,203,444, 4,274,414, 4,834,729, 4,842,578, and 4,705,038; examples of manual endoscopic surgical instruments are described in U.S. Pat. Nos. 4,522,206 and 4,662,371. All of these patents are assigned to the present assignee and are incorporated herein by reference.
The instruments may include a wide variety of surgical implements for performing different types of surgical operations on body tissue. For example, some instruments are equipped with blades for cutting soft tissue, while others have burrs for abrading bone tissue. Still other implements (such as forceps and graspers) grip, rather than cut, tissue.
A typical cutting or abrading endoscopic, e.g., arthroscopic, surgical instrument includes a stationary outer tube within which an inner tube is moved (either manually or driven by a motor) during operation. The surgical implement is mounted to the distal end of the inner tube. Tissue or bone is exposed to the surgical implement through an opening in the distal end of the outer tube, and tissue and/or bone is cut by the moving implement. The cut tissue and bone fragments are drawn through the interior of the inner tube by suction applied at the proximal end of the instrument.
Endoscopic instruments are, whenever possible, used with irrigation devices, such as fluid pumps, which supply irrigating fluid to and suction fluid from the surgical site, as this improves cutting and transport of excised tissue and bone fragments from the surgical site.
Knee arthroscopy, which is performed in a closed capsule, where little danger exists of extravasation of fluid into adjacent anatomical structures, is carried out with the joint infused with saline. The use of fluid in this manner increases the cutting efficiency of powered resectors, and the transport of resected material from the joint. Some other areas of the body where tissue is routinely resected, however, are not generally amenable to infusion of saline. For example, in sinus surgery infusion of the sinuses with saline could potentially result in dangerous extravasation of fluid into the patient's airway.